DETROIT, Jan. 1-(AP)-An automobile engine of steel stamping construction and another employing sleeve valves were described to the Society of Automotive Engineers today as offering a possible answer to increasing costs of manufacture and operations.The SAE, holding its annual meeting here, heard Paul Klotsch, of Cincinnati, tell of the design and construction of a four-cylinder engine fabricated from steel stampings, steel tubing and screw machine parts.The engine, used in the Crosley automobile and weighing 120 pounds, was described as producing better than 26 horsepower at 5,200 revolutions per minute. The cylinder block contains about 125 pieces with copper in sheet, wire or paste form applied in every joint. The assembly is copper-brazed in a 60 foot furnace at 2060 degrees Fahrenheit.Ralph L. Skinner, of Detroit, producer of the sleeve valve engine, said it offered possibilities of reducing car weight as much as 800 pounds. He said the slide valve engine operates without detonation on lower octane fuels, gives better performance and economy and eliminates present troublesome "hot spots."Other benefits, he declared, include compactness. abbreviatedcrankshafts and greater power from less fuel.